The morning glory seeds
themselves which are nativly used in divination(ipomoea violecia)
are native to the mountains of Southern Mexico, West Indies and
Tropical South Americ, contains Lysergic Acid Amide (LSA) which
is closely related in effects to LSD. The most common varients of
Morning Glory seeds containing LSA are; Heavenly Blues, Baby
Woodrose, Flying Suacers, and Pearly Gates. The dosage is rather
vague anywhere from 100 to 500 seeds need to be ingested to
contain the desired effects;

Light-
50-100 seeds

Common-
200-300 seeds

Strong- 300-400 Seeds

Heavy-
400-500 seeds

This is generally the
recommended dosage for consuming LSA seeds. Effects usually last
4 to 8 hours.
People should extract the LSA rather then consuming the seed
right from the package, it has been report that some companies
chemicaly spray their seeds with Mercury, which is highly
pousinous cause the fact that the seeds have been used by teens
for recreational perposes, many companies must state on the
package that they are sprayed to avoid someone being pousinous.
And extraction method can be found here, other methods of extracting can be
found over the internet most likely you should search a reliable
source like www.erowid.org .
if you dont feel like extracting the LSA you could just eat them
out of the back which usually comes in a 1-2g pack. Just remmeber
to check if they are chemicaly sprayed. i strongly recommend
users to first read the popualar Erowid FAQ of Morning Glory Seeds before you do
anything.

And on the legality of these
seeds, distribution or consumption:

While the question may seem
simple, unfortunately there's no clear answer. We are unaware of
anyone who has been prosecuted for ingesting Morning Glory Seeds.
This doesn't mean it couldn't happen, but it's certainly
uncommon. The sale or distribution of the seeds for the explicit
purpose of ingestion is a different question. Again, we are
unaware of anyone who has been prosecuted in such a case, but it
seems somewhat more plausible that it would/could happen,
especially in the case of an individual or organization who was
selling large quantities or to a large number of people. The
closer one gets to the explicit sale or distribution of the seeds
as a drug, the more likely a court would be to find that action
illegal. And as you probably know, the extraction of LSA from the
seeds would also be a significant step towards illegality,
especially if done in large quantities. I know this isn't a
definitive answer, but unfortunately there are no definitive
answers in these cases. In a case such as the one you describe it
seems relatively unlikely that the individuals who ingested the
seeds would be prosecuted for possession of a Schedule III
substance (LSA) and somewhat more possible that those
distributing might face some sort of legal repercussion.